JP2012236387A - Film manufacturing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film manufacturing apparatus for manufacturing a film with even thickness.SOLUTION: The film manufacturing apparatus 10 includes an extruding device 14 extruding a molten film material 12', a stretching device stretching the extruded film material 12', a winding device 18 winding the film 12 onto a winding core 16, a hardness meter 20 measuring the hardness of the wound film 12, and a control means 22 controlling the extruding device 14. The control means 22 controls a pressing means 42 according to the measured hardness, and changes a space between lips 36.

Description

  The present invention relates to a film manufacturing apparatus for manufacturing a long film while winding it around a winding core.

  Conventionally, various methods have been developed for producing a long film (Patent Document 1, etc.). As an example of the manufacturing method, there is a method in which a melted film material is extruded from a T die, stretched in a width direction or a length direction, and wound around a winding core.

  When the film is wound around a winding core in a state where the thickness of the film is not uniform, the pressure applied to the film is different between a thick place and a thin place. The thicker the film, the higher the internal pressure when wound. And in the place where a pressure is high, there exists a possibility that a film may be crushed.

  Therefore, the thickness of the film is measured with a thickness meter before being wound around the core. An example of the thickness meter is a β-ray thickness meter. As shown in FIG. 7, the thickness meter 50 moves in the width direction of the film 12 with respect to the moving film 12 and measures the thickness of the film 12. The point measured by the thickness gauge 50 becomes a locus like a dotted line L. If the thickness of the film 12 is not uniform during the production of the film 12, the thickness of the film 12 is made uniform by changing the parameters of the production apparatus. Since the film 12 having a uniform thickness is wound, the deformation of the film 12 can be prevented.

  However, since both the film 12 and the thickness meter 50 are moving and the measurement point meanders as indicated by the dotted line L, it is difficult to accurately obtain the thickness. Further, since the thickness is measured during the production of the film 12 and the film 12 is before completion, it is difficult to accurately obtain the thickness.

JP-A-8-294964

  The objective of this invention is providing the film manufacturing apparatus for manufacturing the film of uniform thickness.

  The film manufacturing apparatus is formed by extruding a melted film material from an opening of a T-die, a stretching apparatus for stretching the film material extruded by the extruder, and extruding and stretching the film material. A winding device for winding the film around the core, a hardness meter for measuring the hardness of the film wound around the core along the width direction, and an opening width of the T die according to the hardness measured by the hardness meter And control means for changing.

  The film material is extruded from the opening of the T die, and the film material extruded to the stretching apparatus is stretched. After stretching, the film is wound around the core by a winding device. After winding, the hardness meter measures the hardness along the width direction of the film, and the control means changes the opening width of the T die according to the hardness. Further, the stretching device may be omitted, and the hardness of the unstretched film may be measured.

  If the measured hardness is larger than the reference value, the control means narrows the opening width of the T die corresponding to the position of the film having the higher hardness, and if the measured hardness is smaller than the reference value, the control means The opening width of the T die corresponding to the position of the small film is widened. The opening width is controlled by the control means so that the film thickness becomes a predetermined value.

  The hardness meter is a dot-type hardness meter or a hardness meter using ultrasonic waves. A hammer is struck against the film, and the hardness is measured from the deceleration (minus acceleration) of the hammer. Or an ultrasonic wave is emitted to a film and hardness is measured by a reflected wave.

  In the present invention, when the film is wound on the winding core, the uneven thickness is amplified, and the difference in thickness is easy to understand. The opening of the T die is controlled by the thickness of the film, and the thickness of the film can be made uniform. Since the thickness of the film can be made uniform, it is possible to prevent deformation of the internal film when wound up.

It is a figure which shows the structure of a film manufacturing apparatus. It is a figure which shows the structure of T-die, (a) is sectional drawing of T-die, (b) is a front view of opening. It is a figure which shows the film and hardness meter which were wound up. It is a figure which shows an example of the hardness which the hardness meter measured. It is a figure which shows the structure of the film manufacturing apparatus which cut | disconnects a film and measures hardness. It is a figure which shows the structure of the film manufacturing apparatus using a dancer roller. It is a figure which shows the point which measured the thickness by the conventional thickness meter.

  The film manufacturing apparatus of this invention is demonstrated using drawing.

  The film manufacturing apparatus 10 includes an extrusion apparatus 14 that extrudes the melted film material 12 ′, a stretching apparatus (not shown) that stretches the extruded film material 12 ′, and a winding apparatus 18 that winds the film 12 around the winding core 16. A hardness meter 20 for measuring the hardness of the wound film 12 and a control means 22 for controlling the extrusion device 14 are provided (FIG. 1). There is a roller R from the extruding device 14 to the winding device 18, and the extruded film material 12 ′ and the completed film 12 are pressed and moved.

  The film 12 is a long film. Examples of the film material 12 ′ include polystyrene resins, polyethylene resins, polyvinyl chloride resins, polypropylene resins, polyolefin resins, polyester resins, polylactic acid resins, and dicyclopentadiene resins.

  The extrusion apparatus 14 includes an extruder 24 and a T die (T type extrusion die) 26. The T-die 26 includes two T-die bodies 30 having T-shaped grooves 28, with the grooves 28 facing each other (FIG. 2). A T-shaped lateral groove 32 forms a manifold 32 ′, and a T-shaped longitudinal groove 34 is an inlet for the film material 12 ′ and is connected to the extruder 24. The opposite side of the T-shaped longitudinal groove 34 is a lip 36, which forms a gap 38 from the manifold 32 ′ to the tip end portion 37 of the lip 36. A front end portion 37 of the lip 36 is opposed to form an opening 40.

  The film material 12 ′ is extruded in the following order (1) to (4). (1) The film material 12 ′ is press-fitted from the extruder 24 into the manifold 32 ′ through the longitudinal groove 34. (2) The film material 12 'spreads over the entire manifold 32'. (3) The film material 12 ′ passes through the gap 38 from the manifold 32 ′ to the lip 36. (4) The film material 12 ′ is extruded from the opening 40 formed at the tip portion 37 of the lip 36.

  The lip 36 is provided with pressing means 42 and presses the tip portion 37 of the lip 36. The distance between the lips 36, that is, the width d of the opening 40 is changed by the strength of the pressing force. As the pressing means 42, for example, a power means such as an actuator can be used. An actuator is attached to the lip 36, and the power generated by the actuator is transmitted to a rod-like body or the like to press the tip portion 37 of the lip 36. Further, as the other pressing means 42, a metal rod-shaped body pressed against the tip portion 37 of the lip 36 and a device for heating or cooling the rod-shaped body may be used. The metal rod-like body is heated or cooled, and the strength of the pressing force against the tip portion 37 of the lip 36 is changed using the expansion and contraction of the rod-like body. The plurality of pressing means 42 are arranged in the width direction of the T-die body 30. By controlling each pressing means 42, the width d of each part of the opening 40 is controlled.

  The stretching device stretches the extruded film material 12 ′ in the width direction, the length direction, or both. Examples of the stretching device include a belt conveyor that sandwiches both ends of the extruded film material 12 ′ and stretches the film material 12 ′ in the width direction. For example, the width of the extruded film material 12 ′ is stretched from 2.5 m to 5 m. Moreover, in order to perform the extending | stretching of a length direction, the roller which pinches | interposes film material 12 'extruded to two places is arrange | positioned. The rotational speed of the roller on the downstream side in the moving direction of the film 12 is increased. Due to the difference in rotational speed, the film material 12 ′ is stretched in the length direction.

  The winding device 18 winds the film 12 formed by being extruded and stretched on the winding core 16. The winding device 18 includes swinging means. The swinging means corrects meandering of the film 12 by EPC (Edge Position Control). The core 16 is swung in the width direction of the film 12 by EPC, and the film 12 is uniformly wound.

  The hardness meter 20 measures the hardness of the film 12 in the wound state. The hardness meter 20 measures the hardness while moving in the width direction of the film 12 (FIG. 3). Where the film 12 is thick, the hardness increases. Where the film 12 is thin, the hardness decreases. The reason for this will be described. Empirically, the uneven thickness of the film 12 occurs at the same location in the width direction of the film 12. When the film 12 is wound, an air layer is formed between the films 12 in thin portions of the film 12. The thick portion of the film 12 becomes very thick and no air layer is formed. Therefore, the hardness of the wound film 12 varies depending on the thickness of the film 12.

  In the conventional thickness meter, the thickness of one film 12 is measured. However, the present invention measures the hardness of the film 12 stacked in layers. In the present invention, the thickness is increased, and a subtle difference in thickness can be measured.

  The hardness meter 20 is a hardness meter that uses ultrasonic waves. A hardness meter 20 is provided on a rail 44 facing the width direction of the film 12. The hardness meter 20 emits ultrasonic waves to the film 12 while moving along the rails 44 and receives reflected waves. Since the reflected wave differs depending on the hardness, the hardness can be obtained by receiving the reflected wave. The hardness meter 20 may be measured by being arranged at a position where the winding device 18 is located, or may be measured by moving the film 12 by being arranged at another position.

  The control means 22 is a sequencer or a computer for controlling the pressing means 42 attached to the T die 26. The hardness meter 20 measures the hardness as shown in FIG. The control means 22 controls the pressing means 42 according to the measured hardness, and changes the interval between the lips 36 (the width d of the opening 40).

  Each position in the width direction of the film 12 is formed by extruding the film material 12 ′ from a predetermined position in the opening 40 of the T die 26. Therefore, if the measured hardness is larger than the reference value, the opening 40 of the lip 36 of the T die 26 corresponding to the position of the film 12 having a high hardness is narrowed. The lip portion corresponding to the portion having high hardness has a large thickness of the film 12, and the thickness of the film 12 is made thin by narrowing the lip portion of the portion. If the measured hardness is smaller than the reference value, the opening 40 of the lip 36 of the T die 26 corresponding to the position of the film 12 having a low hardness is widened. The lip portion corresponding to the portion having a low hardness has a small thickness of the film 12, and the thickness of the film 12 is increased by widening the lip portion of the portion. The reference value may be a value within a certain range.

  If the ultrasonic hardness meter 20 is used, the hardness is measured while the film 12 is being wound. The opening 40 of the lip 36 of the T die 26 is controlled by measuring the hardness according to the hardness of the film 12.

  As described above, the thickness of the film 12 wound around the winding core 16 indicates the presence or absence of uneven thickness, and the opening width of the T die 26 is adjusted. When the film 12 is wound around the winding core 16, the uneven thickness is amplified, and the difference in thickness is easily understood. Conventionally, since the thickness could not be measured accurately, the thickness of the film 12 could not be controlled, but in the present invention it can be controlled.

  As mentioned above, although embodiment was described about this invention, this invention is not limited to said embodiment. For example, as in the film manufacturing apparatus 10b of FIG. 5, after winding one film 12 around the winding core 16, the film 12 being transferred and the wound film 12 are cut, and then the hardness is measured. good.

  If it is the film manufacturing apparatus 10b of FIG. 5, since it is after the film 12 has been wound up, the hardness meter 20 may be a dot type. The dot-type hardness meter 20 includes a small hammer that is applied to the film 12 and an acceleration sensor that measures the deceleration (minus acceleration) of the small hammer. The hardness meter 20 repeatedly strikes the film 12 while moving in the width direction of the film 12. A small hammer is struck against the film 12 with a constant force, and the deceleration when the acceleration sensor is struck is obtained. If the deceleration is large, the hardness is high, and if the deceleration is small, the hardness is low. As described above, the hardness varies depending on the thickness of the film 12, and uneven thickness can be detected.

  The structure which stops winding of the film 12 and measures the hardness of the film 12 may be sufficient. A dancer roller D is used during the transfer of the film 12 as in the film manufacturing apparatus 10c of FIG. In addition to the dancer roll D, a laser displacement meter 46 for detecting the position of the dancer roll D, a nip roll N provided on the downstream side of the dancer roll D, an upstream side of the dancer roll D, and the speed of the film 12 A first film speedometer 48a to be measured and a second film speedometer 48b provided between the nip roll N and the winding device 18 are provided.

  The laser displacement meter 46 includes a semiconductor laser and a light receiving element. The laser emitted from the semiconductor laser is diffusely reflected by the dancer roll D. A part of the diffusely reflected laser is received by the light receiving element. Depending on the position of the dancer roll D, the light receiving position in the light receiving element is different. The position of the dancer roll D is detected depending on the position of the light receiving element at which light is received. Each of the film speedometers 48a and 48b emits light to the film 12, and detects the speed of the film 12 from a change in reflected light.

  Next, the hardness is detected in the following steps (1) to (5). Even when the hardness is detected, the film material 12 ′ is extruded from the T die 30. (1) The winding speed in the winding device 18 is reduced and the dancer roll D is lowered downward in FIG. The amount that the film 12 is no longer wound is absorbed by the lowering of the dancer roll D. (2) When the winding is stopped, the film 12 is sandwiched by the nip roll N. The film 12 does not move to the winding device 18. (3) The hardness of the film 12 is measured with the hardness meter 20. The dancer roll D is also lowered during the measurement. (4) After measuring the hardness, the nip roll N is opened and the winding is resumed. At this time, the dancer roll D is raised. Moreover, the moving speed of the film 12 is measured by the first film speedometer 48a and the second film speedometer 48b, and the moving speed of the film 12 measured by the second film speedometer 48b is higher than that of the first film speedometer 48a. Increase the winding speed to be faster. (5) When the dancer roll D returns to the original position, the film 12 is taken up by the winding device 18 so that the moving speed of the film 12 measured by the first film speedometer 48a and the second film speedometer 48b becomes the same. Wind up.

  Instead of the laser displacement meter 46, a photoelectric sensor composed of a light emitting element and a light receiving element may be arranged at the upper limit position, lower limit position, and intermediate position of the dancer roll D. The position of the dancer roll D is determined by turning on and off the light receiving element at each position, and the film winding speed is controlled so as to stop the dancer roll D, or the movement speed of the dancer roll D is changed. Control the winding speed.

  Further, if the dancer roll D is suddenly stopped, the film 12 may be damaged. Therefore, at the upper limit position and the lower limit position of the dancer roll D, the film winding speed is controlled so that the moving speed of the dancer roll D gradually decreases as the upper limit position and the lower limit position are approached.

  After winding on the winding core 16, the film 12 may be pulled out, the film 12 may be cut into a plurality of pieces with a cutter, and each may be wound around another winding core. When wound on another winding core, the hardness of the film 12 is measured. Since the film 12 is cut, the hardness meter 20 joins the measured hardness. As for the joining method, the positions of the original film 12 are arranged in order. By joining together, the hardness of one film 12 is obtained.

  When the winding device 18 winds up the film 12, the tension related to the film 12 may be gradually reduced. This is because a large pressure is not applied to the wound inner film 12. By adjusting the pressure, the inner film 12 is hardly crushed.

  In the above embodiment, the film material 12 ′ is stretched, but the present invention can be applied even when the unstretched film 12 is produced. In this case, the stretching device between the extrusion device 14 and the winding device 18 is omitted. The hardness of the unstretched film 12 wound up is measured, and the opening width of the T die 26 is adjusted.

  Further, the unstretched film 12 that has been wound up may be drawn out, stretched, and wound up. In this case, the hardness can be measured by either the unstretched film 12 wound or the stretched film 12.

  Further, the thickness of the film 12 may be measured with a thickness meter from the end of stretching until it is wound up. Both the measurement with the hardness meter 20 and the measurement with the thickness meter are performed. The uneven thickness is inspected by both the thickness meter and the hardness meter 20.

  In addition, the present invention can be carried out in a mode in which various improvements, modifications, and changes are added based on the knowledge of those skilled in the art without departing from the gist thereof.

10, 10b, 10c: Film production device 12: Film 12 ′: Film material 14: Extruding device 16: Winding core 18: Winding device 20: Hardness meter 22: Control device 24: Extruder 26: T-die 28, 32 34: Groove 33 ': Manifold 30: T-die body 36: Lip 37: Lip tip 38: Gap 40: Opening 42: Pressing means 44: Rail 46: Laser displacement meter 48a, 48b: Film speed meter

Claims (4)

An extrusion device for extruding the melted film material from the opening of the T-die;
A winding device for winding the film formed by the extrusion onto a winding core;
A hardness meter for measuring the hardness of the film wound around the core along the width direction;
Control means for changing the opening width of the T die according to the hardness measured by the hardness meter;
A film manufacturing apparatus comprising: The control means includes
If the measured hardness is larger than the reference value, the opening width of the T die corresponding to the position of the film having a large hardness is narrowed,
2. The film manufacturing apparatus according to claim 1, wherein if the measured hardness is smaller than a reference value, the opening width of the T die corresponding to the position of the film having the low hardness is widened. 3. The film manufacturing apparatus according to claim 1, wherein the hardness meter is a dot-type hardness meter or a hardness meter using an ultrasonic wave. The film manufacturing apparatus according to claim 1, further comprising a stretching device that stretches the film material after being extruded.

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